Green’s Dictionary of Slang

(Aus./Irish) ten shillings, a ten-shilling note.

1879		C.J. Kickham Knocknagow 40: The doctor had lighted upon a page where sundry sums were entered, which he himself had received in the shape of half notes and post-office orders.
1949		L. Glassop Lucky Palmer 15: Half a note Vallina all up Anorient.
1951		D. Stivens Jimmy Brockett 17: The boy had his ears back for the ten bob I promised him. [...] I followed the kid out of the lounge, slipped him the half-note.
1959		F. Norman Fings II i: So it’s dahn to flogging clothing-coupons – one fer ’alf a note.
1963		R. McGregor-Hastie Compleat Migrant 105: Arfnote: Ten shillings.
1965		L. Dunne Goodbye to The Hill (1966) 145: I didn’t want to con him for a half-note.
1975		J. Ryan Remembering How We Stood 66: Brendan would come in for a fag, or a ‘lend of a loan’ of half-note.